Power semiconductor module arrangements often include a base plate within a housing. A main substrate is arranged on the base plate. A semiconductor arrangement including a plurality of controllable semiconductor elements (e.g., two IGBTs in a half-bridge configuration) is arranged on the main substrate. A contact element, which allows for contacting the semiconductor arrangement from outside the housing, is usually arranged on a separate substrate that is arranged on the same baseplate as the main substrate, but distant from the main substrate. Electrical connections between the contact element on the separate substrate and the semiconductor arrangement on the main substrate usually include wires such as bonding wires, for example. The main substrate and the separate substrate usually each comprise a substrate layer (e.g., a ceramic layer), a first metallization layer deposited on a first side of the substrate layer and a second metallization layer deposited on a second side of the substrate layer. In some applications the substrates, in particular the metallization layers of the substrates, may be exposed to corrosive gases. When exposed to corrosive gases and further under the influence of electric fields and possibly moisture, dendritic structures may be formed from mobile metal ions of the metallic layer and anions from the corrosive gas (e.g., S2−).
There is a need for a power semiconductor module arrangement that avoids formation of dendritic structures and provides a cost-effective, simple solution that may be manufactured by means of an easy manufacturing method.